A new software engineering topic every day, explained through the problem it solves, with a quiz and a real-world challenge to make it stick.
You added read replicas to take load off the primary, and now users occasionally don't see the record they just created. This shows you how to route reads so each user always sees their own writes without sending all traffic back to the primary.
Server-sent-event or chunked streaming endpoints that emit tokens smoothly on localhost deliver one giant blob after 20 seconds once deployed behind a proxy or CDN. This explains where the chunks are being held and how to force them through.
Your Docker builds reinstall every dependency from scratch whenever you change a single source file, turning a 15-second rebuild into a multi-minute one. This is about the layer ordering (and cache mount) rules that decide whether the install step is reused.
Your async FastAPI/aiohttp service has fast endpoints that suddenly show 2-second p99 latency and failing health checks, even though CPU is at 15%. One synchronous call buried in a handler is stalling the entire event loop.
Your Kafka consumer group keeps rebalancing every few minutes, commits fail with CommitFailedException, and the same messages get processed over and over while lag climbs. This happens when per-record processing is slow enough that your loop misses the poll deadline.
Your service already retries with exponential backoff, yet a 2-second blip turns into a 5-minute outage with traffic arriving in synchronized spikes. This covers why aligned retries amplify load and how jitter plus a retry budget breaks the cycle.